JPH0771521A - Dual type damper pulley - Google Patents

Abstract

PURPOSE:To restrain oscillation so as to improve durability of a second elastic body by reducing the axial length of an inner damper mass, and increasing the radial size to make sufficiently large mass. CONSTITUTION:An outer damper mass 7 which is cylindrical and has a power transmission belt wrapped round the outer peripheral surface thereof is installed on the radial outside of a rim part 3 of a pulley main body 5 having a hub part 2 fitted to a rotary shaft and a cylindrical rim part 3 positioned on the radial outside through a first elastic body 6 in such a manner as to be concentric with the rim part 3. A ring-shaped inner damper mass 10 is installed on the axial outward side end surface of the rim part 3 through a second elastic body 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual type dynamic damper pulley, and in particular, it is attached to a rotary shaft such as a crankshaft of an internal combustion engine and is rotated integrally with the rotary shaft so that it is wound around the outer peripheral surface. A damper mechanism that transmits a rotational driving force to a predetermined succeeding member via a power transmission belt, and that absorbs the vibration of the rotating shaft and reduces the vibration and noise of the rotating shaft and the engine. The present invention relates to a dual type damper pulley equipped with.

[0002]

2. Description of the Related Art As a conventional dual type damper pulley, the one described in Japanese Utility Model Laid-Open No. 62-68053 is known. As shown in FIG. 3, this is a hub portion 2 to which a rotary shaft 1 such as a crankshaft is attached, a cylindrical rim portion 3 located radially outside of the hub portion 2, and a rim portion 3 of the rim portion 3.
The pulley body 5 is composed of the arm portion 4 connecting the hub portion 2 and the hub portion 2. The first elastic body 6 is provided on the outer side of the rim portion 3 in the radial direction.
The outer damper mass 7 is arranged concentrically with the rim portion 3 via the, and the power transmission belt is wound around the outer peripheral surface. Further, the inner damper mass 101 is attached to the arm portion 4 via the second elastic body 100, which is located inside the rim portion 3. The leg portion 104 extending from the flange portion 103 of the set bolt 102 is screwed into the rotating shaft 1 to fix the rotating shaft 1 to the hub portion 2. A stopper metal fitting 106 is attached to an end surface of the head portion 105 of the set bolt 102 in the direction perpendicular to the axis with a mounting bolt 107. The inner damper mass 101 housed in the rim portion 3 is
Of the four holding holes 4A provided in the arm part 4, two holding holes 4A positioned on the diameter of the arm part 4 are provided.
2 through holes 1 extending in the axial direction at the cylindrical wall portion corresponding to
Has 08.

[0003]

In the conventional damper pulley, since the inner damper mass 101 is mounted inside the rim portion 3 and on the arm portion 4 via the second elastic body 100, the diameter of the inner damper mass 101 is reduced. There was a limit to how large. Since the conventional inner damper mass 101 whose diameter is regulated by the inner diameter of the rim portion 3 requires a constant mass, it is necessary to make the length in the axial direction a certain length or more. The direction length had to be almost full. Therefore, the inner damper mass 101 has a structure similar to that of a cantilever, and the swinging motion of the tip becomes large, which may cause the second elastic body 100 to crack and come off. Further, when the second elastic body 100 is molded with rubber, it is necessary to prevent the rubber from protruding at the portion of the arm portion 4 and to remove the burr of the rubber after molding.

Therefore, according to the present invention, the axial length of the inner damper mass is shortened and the radial size is increased to obtain a sufficiently large mass, and the swinging motion is suppressed to improve the durability of the second elastic body. It is an object of the present invention to provide a dual type damper pulley that is improved and prevents the inner damper mass from peeling off from the second elastic body.

[0005]

In order to achieve the above-mentioned object, the present invention has a pulley body having a hub portion attached to a rotating shaft and a cylindrical rim portion located radially outside the hub portion. An outer damper mass, which is cylindrical and has an outer peripheral surface around which a power transmission belt is wound, is attached concentrically to the rim portion on the outer side in the axial direction of the rim portion on the outer side in the radial direction of the rim portion. A ring-shaped inner damper mass is attached to the side end surface via a second elastic body.

[0006]

The outer diameter of the inner damper mass according to the present invention is larger than the outer diameter of the cylindrical portion, and the mass can be sufficiently large without increasing the length in the axial direction. Also,
Since the length in the axial direction is not long, the swinging motion is suppressed, and the durability of the second elastic body for attaching the inner damper mass to the end surface of the cylindrical portion is also improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

In the embodiment shown in FIG. 1, a hub portion 2 to which a rotary shaft 1 such as a crankshaft similar to that shown in FIG. 3 is mounted.
And a radially outer side of the rim portion 3 of the pulley main body 5 including a cylindrical rib portion 3 located radially outside the hub portion 2 and an arm portion 4 connecting the rim portion 3 and the hub portion 2. The outer damper mass 7 is attached to the first via the first elastic body 6. The first elastic body 6 is the outer damper mass 7
And a vulcanization molded integrally therewith in a gap between a metal sleeve 8 which is concentrically arranged inside the rim portion 3 at a predetermined distance and which has a thin cylindrical shape whose length is substantially the same as that of the rim portion 3. ing. The outer damper mass 7 is integrally connected to the pulley body 5 by press-fitting and fixing the metal sleeve 8 on the outer peripheral surface of the rim portion 3. A power transmission belt (not shown) is wound around the outer peripheral surface of the outer damper mass 7.

A second end is formed on the side end surface 3A of the rim portion 3 which is axially outward.
A ring-shaped inner damper mass 10 through the elastic body 9.
Is installed. Also, the outer damper mass 7 also has its end face on the side end face 3A side extended to the opposite side (the axially outward side) from the hub portion 2 side (the axially inner side), and the space 11 is formed at this extended portion. The inner damper mass 10 is formed in this space 11. A hole 10A having the same diameter as that of the hollow portion 3B of the rim portion 3 is formed in the center of the inner damper mass 10, and the rotary shaft 1 is connected to the hub portion 2 by utilizing the hole 10A and the hollow portion 3B of the rim portion 3. Stick to it. The rim portion 3, the second elastic body 9, and the inner damper mass 10 are integrally vulcanized and molded.

When the radial length of the inner damper mass 10 is R and the axial length is W, R> W, and the diameter can be increased, so that the mass can be relatively large. In addition, the length W can be reduced, the bending input due to cantilever can be suppressed, and the swinging motion can be further reduced. In addition, the inner damper mass 10 having such a shape
Is attached to the side end surface 3A of the rim portion 3 via the second elastic body 9, the adhesion area with the second elastic body 9 is increased, and the inner damper mass 10 is less likely to come off.

In the second embodiment shown in FIG. 2, the axial length of the outer damper mass 7 is set to be the same as the axial length of the rim portion 3 so that it does not extend to the side end face 3A side of the rim portion 3. The length R of the inner damper mass 10 is increased in addition to the above. The outer damper mass 7 may be extended to the hub portion 2 side.

In any of the above-described embodiments, the devices such as the engine are present on the right side of the drawing, that is, on the inner side in the axial direction, and the rotary shaft 1 set on the hub 2 is on the right side of the hub 2. Has a flange, and a screw or the like is screwed into the flange from the left side through a plurality of mounting holes 2A to be fixed.

[0013]

As described above, according to the present invention, the rim portion of the pulley main body having the hub portion attached to the rotary shaft and the cylindrical rim portion located radially outside the hub portion. An outer damper mass, which is cylindrical and has a power transmission belt wound around the outer peripheral surface thereof via a first elastic body on the outer side in the radial direction of the, is concentrically attached to the rim portion, and is attached to the side end surface on the axially outer side of the rim portion. Since the ring-shaped inner damper mass is attached via the two elastic bodies, the inner damper mass can have a large radial length, and can have a relatively large mass even if the axial length is shortened. Moreover, since the length in the axial direction can be shortened, the swinging motion due to the cantilever can be suppressed. Furthermore, since the inner damper mass can be lengthened in the radial direction, the adhesive area with the second elastic body also increases.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotating shaft 2 hub part 3 rim part 3A side end surface 5 pulley body 6 first elastic body 7 outer damper mass 9 second elastic body 10 inner damper mass

Claims (1)

[Claims] 1. A pulley body having a hub portion attached to a rotating shaft and a cylindrical rim portion positioned radially outside of the hub portion, and a first elastic body interposed radially outside the rim portion of the pulley body. A cylindrical outer damper mass around which a power transmission belt is wound is attached concentrically to the rim, and a ring-shaped inner damper mass is attached to the side end surface of the rim axially outwardly through a second elastic body. A dual-type damper pulley that is equipped with.